Drip irrigation gets to the root of things

May 5, 2007|By Charlyne V. Schaub Home & Garden Editor

Bruce Adams, water-conservation guru with the South Florida Water Management District, says one of the best ways to keep your container plants watered during the drought is to install a drip irrigation system.

Drip irrigation has several advantages. It wastes less water than traditional irrigation because the water goes directly to the roots of the plants. Because it's more efficient, it loses the least amount of water from evaporation, wind and run-off. It also reduces the chance of your plants getting fungal and insect problems because only the roots, not the leaves, are watered.

"You want to have a minimum of a 20 to 30 percent saturation," Adams says. "You don't want to soak the roots or the plant will rot."

Current Phase II water restrictions allow drip irrigation every day since little water is wasted. Adams suggests watering daily for 10 minutes, but you may have to adjust longer or shorter depending on the container and the plants.

The drip line is attached to an outdoor faucet. Drip emitters attach to the line and apply a consistent amount of water to the plants. Adams suggest one emitter for each 4- to 6-inch pot and two emitters for 1- to 3-gallon pots. Look for these systems at home improvement stores.

But be careful, he says, that the drip irrigation does not cause run-off, which is prohibited during water restrictions.

Pamela Crawford, author of Instant Container Gardens, used drip irrigation on her containers because hand watering was too time consuming. At first she used a timer, but she found it difficult to use so she turned on the hose when she wanted to water.

Crawford says it's a good idea to check the emitters frequently.

"The one disadvantage is you have to be sure the emitters work because they can get clogged," she says. "Well water clogs them more than city water. Also sometimes an emitter would fall out of the pot, and I didn't notice it until the plant wilted."

One final suggestion: Make sure you know when the container needs water.

Water your plants only when they show signs of wilt or the soil feels dry. To test the soil dryness, push your finger into the soil about an inch.

"Knowing when to water is important because many container plants die from overwatering," Crawford says. "If your plant appears wilted and the soil has been wet for several days, you have probably drowned the plant and it will probably die."

FACTORS THAT AFFECT WATER USE

Pamela Crawford has been an apostle of drought-tolerant gardening for many years. She wrote her master's thesis at Florida International University on low-water landscaping for Florida and has been including water conservation in her gardening books.

Here are some of her suggestions:

1. Shade is best. Plants in the shade will use one-third to one-half as much water as those in full sun.

2. Avoid windy locations. Windy conditions cause plants to require more water because the water evaporates.

3. Avoid light-colored walls. A light-colored wall facing south with no shade reflects light and makes plants require more water. If you choose this location, succulents are a better bet.

4. Select the best soil. Look for good -quality potting soil mix, which includes peat moss. It holds water better than the cheaper soils, which contain a lot of sand.

5. Look for plant with low water needs. Some of your best bets include: succulents, pentas, grasses (juncos, also called rush, and fountain grass), trailing torenia, coleus, verbena and scaevola `Blue Wonder.'

6. Big containers are better. Plants will require less water if they are small plants in a larger container. Avoid filling small containers to the brim with plants.

7. Repotting is important. As plants remain in pots for more than a year, their roots fill the pot, leaving less room for water.